package collection;

import java.util.ArrayList;
import java.util.Collection;

/** 集合:
 *      Collection接口的演示
 */
public class CollectionDemo {
    public static void main(String[] args) {
        Collection c  = new ArrayList();
        c.add(new Point(1,2));
        c.add(new Point(3,4));
        c.add(new Point(5,6));
        c.add(new Point(7,8));
        c.add(new Point(9,0));
        c.add(new Point(1,2));
        //[元素1.toString(), 元素2.toString() ,元素3.toString()......]
        System.out.println(c);//[(1,2), (3,4), (5,6), (7,8), (9,0), (1,2)]

        /*
            boolean contains(Object o):
            判断当前集合是否包含给定元素o
            判断依据是给定元素是否与当前集合存在equals()比较为ture的情况
         */
        Point p = new Point(1,2);
        boolean contains = c.contains(p);
        System.out.println("是否包含:"+contains);//true

        /*
            boolean remove(Object o):----一般不接收boolean结果
            从当前集合中删除给定的元素o的equals()比较为true的元素
            若集合中有重复元素则删除一次
         */
        c.remove(p);
        System.out.println(c);

        c.remove(p);
        System.out.println(c);

        Collection cc = new ArrayList();
        Point pp = new Point(1,2);
        cc.add(pp); //将pp添加到cc中----将pp的引用(地址)装到了cc中
        System.out.println("pp:"+pp);//(1,2)
        System.out.println("cc:"+cc);//[(1,2)]

        pp.setX(100);
        System.out.println("pp:"+pp);//(100,2)
        System.out.println("cc:"+cc);//[(100,2)]



        /*
        Collection c = new ArrayList();
        c.add("one");
        c.add("two");
        c.add("three");
        c.add("four");
        c.add("five");
        //集合重写了Object类的toString()方法
        System.out.println(c);//[one, two, three, four, five]
        System.out.println("size:"+c.size());//5     size(); 输出集合的个数
        //isEmpty() 判断集合是否为空集(size()长度为0,也表示空集)
        System.out.println("是否为空集:"+ c.isEmpty());//false

        c.clear();  //清空集合
        System.out.println("集合已清空");
        System.out.println("集合长度为:"+c.size()); //输出集合c的长度
        System.out.println("是否为空集："+c.isEmpty());//true   判断集合是否为空集
        System.out.println(c); //[]

         */












    }
}
